During the morning of Monday, May 25th, a single thunderstorm developed in Wabasha County and moved northward into Pepin County. This storm formed along a weak surface boundary across southeast Minnesota.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MPX wrote it up.
During the morning of Monday, May 25th, a single thunderstorm developed in Wabasha County and moved northward into Pepin County. This storm formed along a weak surface boundary across southeast Minnesota. Severe weather parameters were weak but the morning sounding at the MPX NWS indicated MUCAPEs of around 200-300 J/kg. Mid-level lapse rates were moist adiabatic of around 6.5 c/kg between 850-500 mb. Freezing levels were around 10,500 feet with bulk shear values of 30-35 kts. These parameters were enough to produce severe weather from the city of Pepin, north-northeast to Durand. This storm weakened as another storm developed in eastern Pepin County and moved northeast into Eau Claire and Chippewa Counties of west central Wisconsin. More severe hail reports were noted, but there was a brief downburst that caused damage in the northwest part of Eau Claire, Wisconsin.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Twin Cities, MN wrote its last area forecast discussion before the first event at May 25, 6:13 AM CST, 1 hour 17 minutes earlier.
Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 713 AM CDT Mon May 25 2020 .Updated for 12Z Aviation Discussion... Issued at 701 AM CDT Mon May 25 2020 && .SHORT TERM...(Today through Tuesday) Issued at 430 AM CDT Mon May 25 2020 By this morning, a remnant MCV will lift northeast into the area with the potential for another Monday night. Showers will accompany the MCV, moving across eastern Minnesota and west- central Wisconsin leaving behind another day of overcast skies. Temperatures will rebound into the upper 70s/low 80s despite the cloud cover. CAMs try to develop another round of showers and thunderstorms from a potential MCV Monday evening. Forecast soundings show MLCAPE values between 500 to 1000J/kg with poor lapse rates and weak vertical wind shear, limiting the severe threat. However, if storms develop there will still be the potential for gusty winds and small hail. Monday evening convection will be dependent on the convective trends across the southern Plains. The final system from the southern Plains trough will lift north across the region Tuesday. After this time, the trough will cut off over Texas and end the train MCVs. For Tuesday, expect high temperatures in the upper 70s with mostly cloudy conditions. Tuesday afternoon/evening presents another chance of showers and thunderstorms. Potential thunderstorm development will be favored across eastern Minnesota and western Wisconsin ahead of the surface front where atmospheric instability will be the greatest. .LONG TERM...(Tuesday night through Sunday) Issued at 430 AM CDT Mon May 25 2020 Zonal flow north of the cutoff system midweek will give way to troughing across the north central and northeastern U.S. late week and next weekend. A brief shot of cooler and drier air will accompany the trough and surface high pressure on Friday. The airmass behind the trough will be relatively dry, keeping the rain chances out of the area for the rest of the forecast period. High temperatures will remain in the low/mid 70s into next weekend. Expect the cool down to be brief as both EPS/GEFS ensembles continue to build the ridge back northeast from the Rockies late weekend and the following week as the trough lifts away. Looking ahead into the first week of June, the CPC outlooks favor above normal temperature probabilities. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) Issued at 701 AM CDT Mon May 25 2020 Generally VFR conditions today and tonight, but we'll see a few scattered showers and thunderstorms over the next 24 hours, along with early morning patchy fog today and again on Tuesday. Winds will be light and variable. Although there is a chance for thunder, confidence was too low to include mention in the TAF. KMSP... Generally VFR conditions today and tonight, but we'll see a few scattered showers and thunderstorms over the next 24 hours, along with early morning patchy fog today and again on Tuesday. Winds will be light and variable. Although there is a chance for thunder, confidence was too low to include mention in the TAF. /OUTLOOK FOR KMSP/ Tue...VFR/MVFR with -TSRA possible. Wind NW at 5-10 kts. Wed...VFR. Wind W/NW at 5-10 kts. Thu...VFR. Wind NW at 10-15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && SHORT TERM...BPH LONG TERM...BPH AVIATION...JRB
Hazardous Weather Outlook National Weather Service Twin Cities/Chanhassen MN 444 AM CDT Mon May 25 2020 MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028- 260945- Douglas-Todd-Morrison-Mille Lacs-Kanabec-Stevens-Pope-Stearns- Benton-Sherburne-Isanti-Chisago-Lac Qui Parle-Swift-Chippewa- Kandiyohi-Meeker-Wright-Hennepin-Anoka-Ramsey-Washington- Yellow Medicine-Renville-McLeod-Sibley-Carver-Scott-Dakota- Redwood-Brown-Nicollet-Le Sueur-Rice-Goodhue-Watonwan-Blue Earth- Waseca-Steele-Martin-Faribault-Freeborn-Polk-Barron-Rusk- St. Croix-Pierce-Dunn-Pepin-Eau Claire- 444 AM CDT Mon May 25 2020 This Hazardous Weather Outlook is for portions of central and southern Minnesota...and west central Wisconsin. .DAY ONE...Today and Tonight. Patchy fog possible this morning, then a chance for thunderstorms later today and tonight. The threat for severe weather is low, but a few storms could produce gusty winds and brief downpours. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. There is a chance for thunderstorms through Tuesday night. The threat for severe weather is low, but a few storms could produce gusty winds and brief downpours. .SPOTTER INFORMATION STATEMENT... SKYWARN spotter activation will not be needed. jrb
The La Crosse radar (KARX), 103 km away, was scanning. The volume nearest the first event began at 13:30 UTC.
5 hail, 1 thunderstorm wind. Local standard time, as filed.
A social media picture indicated 2 inch diameter hail fell in Pepin. Numerous spotters also reported hail as large as 2 inches in Pepin.
There were reports of large hail, up to quarter size, that fell in a swath between Ella and Porcupine.
Spotters reported several trees down, and there was a picture of a large tree uprooted south of North High School in Eau Claire. Other damage was noted to the high school tennis court fence that was blown down. Other small trees and limbs were blown down around the vicinity of the high school.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2020Every state in 2020This day in weather historyWarnings in Wisconsin, May 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 883346, 883347, 883348, 883349, 883636, 883350.